1. Technical Field
The invention relates to axial flow blood pumps having useful stator blade and conduit configurations.
2. Background Information
Axial flow pumps are useful in a variety of fluid pumping applications. A number of implantable axial flow blood pumps, for example, presently are under development for application as either artificial hearts or cardiac assist devices. An axial flow blood pump typically includes a blood flow conduit that defines a cylindrical blood flow channel, an impeller mechanism mounted within the blood flow channel, a rotor coupled to actuate the impeller mechanism for blood pumping action, and an electric motor stator for actuating the rotor by electromagnetic force. The impeller blades can be mounted directly on the rotor. In this case, the rotor may form an elongated member that extends axially along the cylindrical blood flow channel. The impeller blades can be mounted about the rotor, for example, in a spiral-like pattern. Alternatively, the impeller blades can be mechanically coupled to the rotor via a transmission shaft.
An axial flow blood pump typically includes outlet stator blades that redirect rotational blood flow generated by the impeller blades. The outlet stator blades are positioned adjacent the outlet end of the rotor. In some cases, the outlet stator blades can be integrally formed with or attached to a stator hub that supports the outlet end of the rotor. In particular, the stator hub can be configured as a bearing that receives the outlet end of the rotor and supports the rotor for rotation about its longitudinal axis. The stator blades generally extend radially outward from the stator hub to the inner wall of the cylindrical blood flow channel. The outlet stator blades serve to direct the blood flow such that the tangential velocity components are re-oriented in the axial direction.